From 65d2f0bc65b0249a22a6c1f49ec29ee5e2980c7b Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 21 Jul 2007 17:09:51 +0200 Subject: [PATCH] x86: Always flush pages in change_page_attr Fix a bug introduced with the CLFLUSH changes: we must always flush pages changed in cpa(), not just when they are reverted. Reenable CLFLUSH usage with that now (it was temporarily disabled for .22) Add some BUG_ONs Contains fixes from Mathieu Desnoyers Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/mm/pageattr.c | 20 +++++++++++++++++--- arch/x86_64/mm/pageattr.c | 23 ++++++++++++++--------- 2 files changed, 31 insertions(+), 12 deletions(-) diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c index 37992ffb1633..8927222b3ab2 100644 --- a/arch/i386/mm/pageattr.c +++ b/arch/i386/mm/pageattr.c @@ -82,7 +82,7 @@ static void flush_kernel_map(void *arg) struct page *p; /* High level code is not ready for clflush yet */ - if (0 && cpu_has_clflush) { + if (cpu_has_clflush) { list_for_each_entry (p, lh, lru) cache_flush_page(p); } else if (boot_cpu_data.x86_model >= 4) @@ -136,6 +136,12 @@ static inline void revert_page(struct page *kpte_page, unsigned long address) ref_prot)); } +static inline void save_page(struct page *kpte_page) +{ + if (!test_and_set_bit(PG_arch_1, &kpte_page->flags)) + list_add(&kpte_page->lru, &df_list); +} + static int __change_page_attr(struct page *page, pgprot_t prot) { @@ -150,6 +156,9 @@ __change_page_attr(struct page *page, pgprot_t prot) if (!kpte) return -EINVAL; kpte_page = virt_to_page(kpte); + BUG_ON(PageLRU(kpte_page)); + BUG_ON(PageCompound(kpte_page)); + if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) { if (!pte_huge(*kpte)) { set_pte_atomic(kpte, mk_pte(page, prot)); @@ -179,11 +188,11 @@ __change_page_attr(struct page *page, pgprot_t prot) * time (not via split_large_page) and in turn we must not * replace it with a largepage. */ + + save_page(kpte_page); if (!PageReserved(kpte_page)) { if (cpu_has_pse && (page_private(kpte_page) == 0)) { - ClearPagePrivate(kpte_page); paravirt_release_pt(page_to_pfn(kpte_page)); - list_add(&kpte_page->lru, &df_list); revert_page(kpte_page, address); } } @@ -236,6 +245,11 @@ void global_flush_tlb(void) spin_unlock_irq(&cpa_lock); flush_map(&l); list_for_each_entry_safe(pg, next, &l, lru) { + list_del(&pg->lru); + clear_bit(PG_arch_1, &pg->flags); + if (PageReserved(pg) || !cpu_has_pse || page_private(pg) != 0) + continue; + ClearPagePrivate(pg); __free_page(pg); } } diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c index 9148f4a4cec6..36377b6b8efe 100644 --- a/arch/x86_64/mm/pageattr.c +++ b/arch/x86_64/mm/pageattr.c @@ -74,14 +74,12 @@ static void flush_kernel_map(void *arg) struct page *pg; /* When clflush is available always use it because it is - much cheaper than WBINVD. Disable clflush for now because - the high level code is not ready yet */ - if (1 || !cpu_has_clflush) + much cheaper than WBINVD. */ + if (!cpu_has_clflush) asm volatile("wbinvd" ::: "memory"); else list_for_each_entry(pg, l, lru) { void *adr = page_address(pg); - if (cpu_has_clflush) - cache_flush_page(adr); + cache_flush_page(adr); } __flush_tlb_all(); } @@ -95,7 +93,8 @@ static LIST_HEAD(deferred_pages); /* protected by init_mm.mmap_sem */ static inline void save_page(struct page *fpage) { - list_add(&fpage->lru, &deferred_pages); + if (!test_and_set_bit(PG_arch_1, &fpage->flags)) + list_add(&fpage->lru, &deferred_pages); } /* @@ -129,9 +128,12 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, pte_t *kpte; struct page *kpte_page; pgprot_t ref_prot2; + kpte = lookup_address(address); if (!kpte) return 0; kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK); + BUG_ON(PageLRU(kpte_page)); + BUG_ON(PageCompound(kpte_page)); if (pgprot_val(prot) != pgprot_val(ref_prot)) { if (!pte_huge(*kpte)) { set_pte(kpte, pfn_pte(pfn, prot)); @@ -159,10 +161,9 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, /* on x86-64 the direct mapping set at boot is not using 4k pages */ BUG_ON(PageReserved(kpte_page)); - if (page_private(kpte_page) == 0) { - save_page(kpte_page); + save_page(kpte_page); + if (page_private(kpte_page) == 0) revert_page(address, ref_prot); - } return 0; } @@ -234,6 +235,10 @@ void global_flush_tlb(void) flush_map(&l); list_for_each_entry_safe(pg, next, &l, lru) { + list_del(&pg->lru); + clear_bit(PG_arch_1, &pg->flags); + if (page_private(pg) != 0) + continue; ClearPagePrivate(pg); __free_page(pg); } -- GitLab